#include <ros.h>
#include <std_msgs/Empty.h>

ros::NodeHandle nh;


void messageCb(const std_msgs::Empty& toggle_msg)
{
  digitalWrite(13, HIGH-digitalRead(13));   // blink the led
}

ros::Subscriber<std_msgs::Empty> sub("toggle_led", &messageCb );


void setup()
{
    pinMode(13, OUTPUT);
    nh.initNode();
    nh.subscribe(sub);
}

void loop()
{
  nh.spinOnce();
  delay(1);
}

